You can definitely do this.
I replaced a faulting 1TB disk with a 2TB disk; it did rebuild the array, then I replaced the non-faulting 1TB disk with another 2TB disk. After the second rebuild, you need to go in and adjust the device size in the RAID manager software (which you can't do whilst the rebuilds are taking place).
The RAID manager software I used was "Adaptec Storage Manager" --> Actions "Expand or Change Logical Drive". Then I increased the size and let it reconfigure the device.
The reconfiguring started at 50% and took a very long time, but it eventually finished.
After that, I had to increase the file system (NTFS on W2K8 server), but I had to rescan the disks first (diskmgmt.msc). After increasing the NTFS size to take up all the extra space (which shows as unallocated space), the server was somewhat non-responsive, a reboot fixed this and everything is working fine now with the file system seeing the new full capacity.